public static class My97DatePicker    {        private static string defaultFormat = "yyyy-MM-dd";        /// <summary>          /// 使用特定的名称生成控件          /// </summary>          /// <param name="helper">HtmlHelper对象</param>          /// <param name="name">控件名称</param>          /// <returns>Html文本</returns>          public static MvcHtmlString Calendar(this HtmlHelper helper, string name)        {            return Calendar(helper, name, defaultFormat);        }        /// <summary>          /// 使用特定的名称生成控件          /// </summary>          /// <param name="helper">HtmlHelper对象</param>          /// <param name="name">控件名称</param>          /// <param name="format">显示格式</param>          /// <returns>Html文本</returns>          public static MvcHtmlString Calendar(this HtmlHelper helper, string name, string format)        {            return GenerateHtml(name, null, format);        }        /// <summary>          /// 使用特定的名称和初始值生成控件          /// </summary>          /// <param name="helper">HtmlHelper对象</param>          /// <param name="name">控件名称</param>          /// <param name="date">要显示的日期时间</param>          /// <returns>Html文本</returns>          public static MvcHtmlString Calendar(this HtmlHelper helper, string name, DateTime date)        {            return Calendar(helper, name, date, defaultFormat);        }        /// <summary>          /// 使用特定的名称和初始值生成控件          /// </summary>          /// <param name="helper">HtmlHelper对象</param>          /// <param name="name">控件名称</param>          /// <param name="date">要显示的日期时间</param>          /// <param name="format">显示格式</param>          /// <returns>Html文本</returns>          public static MvcHtmlString Calendar(this HtmlHelper helper, string name, DateTime date, string format)        {            return GenerateHtml(name, date, format);        }        /// <summary>          /// 通过lambda表达式生成控件          /// </summary>          /// <param name="helper">HtmlHelper对象</param>          /// <param name="expression">lambda表达式，指定要显示的属性及其所属对象</param>          /// <returns>Html文本</returns>          public static MvcHtmlString CalendarFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression)        {            return CalendarFor(helper, expression, defaultFormat);        }        /// <summary>          /// 通过lambda表达式生成控件          /// </summary>          /// <param name="helper">HtmlHelper对象</param>          /// <param name="expression">lambda表达式，指定要显示的属性及其所属对象</param>          /// <param name="format">显示格式</param>          /// <returns>Html文本</returns>          public static MvcHtmlString CalendarFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression, string format)        {            string name = ExpressionHelper.GetExpressionText(expression);            DateTime value;            object data = http://www.mamicode.com/ModelMetadata.FromLambdaExpression(expression, helper.ViewData).Model;            if (data != null && DateTime.TryParse(data.ToString(), out value))            {                return GenerateHtml(name, value, format);            }            else            {                return GenerateHtml(name, null, format);            }        }        /// <summary>          /// 通过lambda表达式获取要显示的日期时间          /// </summary>          /// <param name="helper">HtmlHelper对象</param>          /// <param name="expression">lambda表达式，指定要显示的属性及其所属对象</param>          /// <param name="format">显示格式</param>          /// <returns>Html文本</returns>          public static MvcHtmlString CalendarDisplayFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression, string format)        {            string name = ExpressionHelper.GetExpressionText(expression);            DateTime value;            object data = http://www.mamicode.com/ModelMetadata.FromLambdaExpression(expression, helper.ViewData).Model;            if (data != null && DateTime.TryParse(data.ToString(), out value))            {                return new MvcHtmlString(value.ToString(format)) ;            }            else            {                return new MvcHtmlString("");            }        }        /// <summary>          /// 通过lambda表达式获取要显示的日期时间          /// </summary>          /// <param name="helper">HtmlHelper对象</param>          /// <param name="expression">lambda表达式，指定要显示的属性及其所属对象</param>          /// <returns>Html文本</returns>          public static MvcHtmlString CalendarDisplayFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression)        {            return CalendarDisplayFor(helper, expression, defaultFormat);        }        /// <summary>          /// 生成输入框的Html          /// </summary>          /// <param name="name">calendar的名称</param>          /// <param name="date">calendar的值</param>          /// <returns>html文本</returns>          private static MvcHtmlString GenerateHtml(string name, DateTime? date, string format)        {            string str = "";            if (date != null)            {                str= "<input type=\"text\" id=\"" + name + "\"  onclick=\"WdatePicker({el:‘" + name + "‘})\" class=\"Wdate\" value=http://www.mamicode.com/"" + date.Value.ToString(format) + "\" />";            }            else            {                str= "<input type=\"text\" id=\"" + name + "\"  onclick=\"WdatePicker({el:‘" + name + "‘})\" class=\"Wdate\" value=http://www.mamicode.com/"\" />";            }            return new MvcHtmlString(str);        }    }